Chiral bisoxazolines are among the most useful catalysts in asymmetric organic reactions. Heterogeneous catalysts are desirable as they provide for easier, faster and more efficient separation and recovery of the catalyst. Consequently a great deal of research has been done to heterogenize chiral bisoxazolines. While most heterogenized bisoxazolines involve the use of polymer supports, a number of silica-supported bisoxazoline catalysts have been developed. These silica-supported bisoxazolines typically show lower enantioselectivities and reactivities than their homogeneous counterparts.
There is therefore a need for a bisoxazoline catalyst that provides for easy separation of the catalyst from products and provides good enantioselectivity and reactivity.